Rheostatic motor controller



Nov. 9, 1943. K. PERKINS 2,333,814 y RHEOSTTIC MOTOR CONTROLLER Filed aIGh 1l, 1942 Patented Nov. 9, 1943 Y umn-:o

` HmnaosrArxoMoron YsTAI'LIISS PATENT OFF-,ICE

CONTROLLER `Kenneth Perkins., Scotch Plains;`N.'.I., assigner y to The Singer Manufacturingicompany, Elizf abeth,'N. J., a corporation oi.' New Jersey Appucatibn Mattan, 1942, serial Nt. 34,2412

*9 Claims. (o1. 201-51) 1g a-:simple vand rugged operating mechanism com-` prising few parts. .I .Y

Another vobject of'thisinventio'n is to provide an inexpensive. vmetz-controller comprising two easily molded interfltting parts that may be readily assembled together with a single fasteningelementJriff rAstillfurther object of the invention is toprofvide a'rheostati'c motor controllerwhich isre'ndered .substantially dust-proof by a .telescopic construction which makes it unnecessary to bring an actuator'elementoutthrough an vaperture in the casing.4 f

With the above and other objects in view.,fas will hereinafter appear, the invention comprises fthe' combinations and arrangements of parts hereinafter set forth and illus'tratedin the accompanyingdrawing of a preferred embodiment vof the invention, from which the several features off the invention and the advantages attained A'thereby will be readily understood by those skilled inthe art. In the accompanying drawingf Fig.v l is a plan view'oi" a rheostatic motor controller embodying the invention. f1 Fig. v2 is a vertical section, partly in elevation, 'taken on the-line 2 2, Fig. 1. J

" Fig. 3i`s a horizontal section, partly in plan, taken on theline 3 3, Fig. 2.

Fig.` 4`is a fragmentary vertical section, partly ff in elevation, taken substantiallyfon theline4 4, Fig. 2.1 v

^ Fig. 5 isa fragmentary verticalsection, partly 4in elevation, takenv substantially on the line 5 5,

Fis.'1."

Referring `more specifically to the drawing, there .isv shown aimotor controller comprising a lr disk-likebase I`-preferably made of molded insulating-material andformed with a centrally-disposed upstanding body portion 2 and an upstandl'ing peripheral edge'portion 3 as seenbest in' Fig. -2. l Formed within the body portion 2 is acentral axial `guide-aperture 4, surrounded symmetrically l#by f'vertical cylindrical: receiving pockets 5 .posi- "tionedrtin" ai Y regular hexagonal arrangement.

to form together a casing for the controller.

Seated .withineach of said pockets 5 is astackof carbon disks '6 arranged` between the bottom portion of said pockets and a movablecontac't stud .1 positioned on the top of each stack. A flanged spacer'collar 8, pressed within the top of each pocket 5. surrounds each ,of `said studs to `center and. to retain it within `the pocketand pto provide a vertical bearing surface for its movement. Electricalbridging conductors 9.are Aembedded .within the body portion 2 and extend between the bottom portionsof certain ones of said sockets -tomake electrical contact with the bottom of the `stack ofdisks therein and to series connect said stacks together in pairs` as seen in Fig. 3. Also partially embeddedin the ,body portion 2 of the base I arethe L-shaped terminal lugs I0, each of which connects atone end with the bottom disk of one of two adjacent stacks and at `the other end terminates ina portion which receives .a terminal screw II formaking connection with leads I2, whereby the device may be connected into any desirable external circuit- An inverted cup-shaped movable pedal membe .I3`, preferably made of moldedinsulating material, is formed with a` downturned peripheral edge portion I4 which is adapted to encompass thecomplemental upturned edge portion 3 of the baserl sothat said pedal member rI3 and said base I are partially telescoped in a coaxialk position A verticallyy disposed guide-rib I5 formed in the edge .portion I4` extends radially inward and is vengaged within a complemental slot portion I6 formed in the peripheral edge portion 3 of the base I so that said pedal member is constrained to move verticallyand coaxially relative to said base I. t

Thedomed pedal member I3 is formed with a vertically depending central boss member Il radapted to slide vertically within a portion I8 of the guide aperture 4 in order to maintain the base land the pedal member in coaxial align ment. ...A headed screw `.III,.tlneadedinto the central portion of guide boss I'Lextends vertically yfrom the lower partof the aperture 4 upward and through a portion 20` of reduced diameter forming a stop .shoulder to limit the upward `travel ofsaid screw and prevent the complete separation of the base I and the pedal member I3. A helical reaction spring .2| embracing the boss `member 11 and having its ends received in annular recesses 22 and 23 in the pedal member and base respectively,gis provided to balance the operating pressures appliedV by. thefoot of the operator andito biassaid pedal member to a raised `peda1 member.

and bridge respective pairs of the carbon disk stacks in the base member and.' thus cooperate with the fixed bridging conductors 9 to connect all of the stacks in series relation, as seen best in Fig. l. The reaction spring 2| lifts the pedal member I3 high enough, when the foot pressure is removed therefrom, so that the bow-springs 24 distributed series of reaction points against which the pedal member bears.

The base and pedal members are of readily moldable shape, and assembly has been reduced to a few simple screw-driver operations by the use of inserts within the molded parts. It is notable that the movable and stationary elements are operatively secured together .by the Snle screw I S.

uIbn operation, when thezootof the operator is pressed down upon the pedal centrally at the top, the guide boss I1 descends slldably within the A"guide"ai'ertue"portion I8 in opposition to the leave the surfaces of contact studs 1 and thus y contact with and short-circuit the terminal lugs u I0 when the pedal member I3 is suilicientlydepressed, as shown best in Fig. 4. This short-circuit across the terminals of the controller effectively by-passes the resistance afforded by the stacks of carbon disks after they have been com- I;

pressed sufficiently by downward pressure on the pedal member I3. This provides a position of minimum resistance for the controller.

The base I is formed at the peripheralK edge with a slight radial flange portion 28. This flange i portion has fitted over it an annular cushioning shoe 29 made of rubber or other suitable resilient material, which shoe underlies the base I at the periphery andserves as a resilient support for the controller. sistance against the sliding of the unit over4 any supporting surface on which it may be placed but also helps to prevent thescratching and marring of said surface.

The edge portions 3 and I4 are formed with slots 30 and 3|, respectively, to provide exit clearance for the cord '32 containing the leads Il, This vclearance provides the only means of access |to the interior of the controller for external dirt and dust and may be made Very small to exclude subary elements, entirely eliminates the need for theusual operating mechanisms comprising.` pivots, links and levers. Further, by segregatingthe total series resistance into a number. of individual resistance units represented by the 'separate stacks, it has been possible to use thesejstaclrsv as direct supporting elements for the movable Ther symmetrical arrangement of the stacks 6 about'the guide aperture 4 assists in holdingr'the pedal'fmember .I3 in coaxial align- 'ment with the base I by providing auniformly.

This support not only provides repressure exerted by the reaction spring 2l.

In thisfde's'cent, the'cornplemental edge portions 3 'd' I4 `4 offybavs'e and pedal respectively are maintaned incoaxial slidable telescoped relation and 'thecoriductingfbw springs 24, secured to the pedal, `irst make contact with the studs 1 to connectelectrically in series relation the pairs of stacks permanently 'connected 'in pairs 'bythe embedded "conductors "9. `Further l-downward movement ofthe-pedal Iapplies anf increasing pressure to the stacks with an attendant dem in `their effective-electrical resistance. *Atteia suilicient 'downward displacement" 'of -the'pedalfis reached, `the curved terxrzinal""portions'2Gb'ofV the conducting member 23; make contact 1 with* 'the terminal lugs I0 toprovide ashortecircuit around the terminals' ofthe controller. '-A" slight: further downward movement: of the" pedal Ii ybrings' the free end of the boss member Il tota stop against the shoulder formed-"byI the reduced portion 20 of the aperture I8. 'Thislirnitsthe-maximum downward position` vofY the; cntroller/ pedal.

From lthe ioregomgfit wilrbel perceived that I have provided an improved and simplified motor controller 1 comprising readily ,-moldablef "coaxial telescopingfparts easily. assembled; together with few fastening means into* an substantially; dustproof casing of pleasing appearance anni` contaming ai plurality `of" verticalrvaxis. stacksrof. carbon disks distributed horizontally in a regular pattern.` l

lIt will be 'obvious to those Skil-leali;Y theatt thatv the invention ;may, without departure from its` essentiarattributes. be embodied: irl-various specific forms other:` than those shown` and described, whichlatterare; to be considered-in all respects as illustrative 'of 'theY invent-ionand: not restrictive, reference being had to` the` appended claims rather than to the foregoing description vto indicate the scqpefofthe invention.

Having thus set forththefntllle'of; the invention what I claim hereinis: f

l.' A rheostatic motor-controller having4 a body-member formedfwitha broad nat base `adapted `to restqfor use upon-,thev por and a vertical axis cylindricalfportionf rising., from' Said `lgiase andfhavng a; plurality. Qf w e1ls, compres- -sible carbon resistance material-disposedfin'said wells, a pedal cap-member movable vertically upon thexcylindrical portionxof said; base,'and

onel or more bowf-springj` bridging; contact members mounted on and within said cap-member ,in cooperative.relation'with the compx'cssibleresistance material containtiiin said; wells.

2.A rheostatic controller comprising-answer stationary basemember formed; with @plurality of upright cylindrical receiving pockets; distributed horizontally in a vregularpattern; Stwkepf carbon disks retained` within said pocketsk and lan upper inverted 'cupzshapedf pedali member "positionedM ink telescoping reiationwith member andmovable :relative :to'said base? member along a vertical linear axis and spring means mounted directly upon and within said pedal member to electrically connect said stacks in series pairs and to vary the pressure on said stacks.

3. 'A rheostatic controller comprising a lower upright cylindrical stationary base member having a vertical axis of symmetry and formed with a plurality of generally cylindrical receiving depressions located equidistantly from said axis of symmetry and from each other and having their axes substantially parallel to the axis of said base member, stacks of carbon disks retained within said depressions, and an upper inverted cup-shaped pedal member biased to a raised position and arranged in coaxial telescoping relation with said base member and movable axially downward from said raised position and resilient means carried by said pedal member to electrically connect said stacks in series pairs.

and to apply increasing pressure on said stacks during the downward movement, said pedal member being constrained to move substantially in an axial direction only.

4. A rheostatic controller comprising Va lower stationary base member having a vertical `axis of symmetry and formed with more than two embedded column-shaped receiving pockets having their axes substantially parallel to and symmetrically spaced about said vertical axis of symmetry, stacks of carbon disks retained within said pockets, and an upper inverted cup-shaped pedal member carrying resilient current-conducting means and positioned in coaxial telescoping relation with said base member and biased to a raised position with said current-conducting means out of contact with said stacks and movable axially downward to electrically connect the stacks in series pairs and apply increasing pressure to said stacks.

5. A rheostatic controller comprising a generally cylindrical stationary base member with a plurality of generally cylindrical receiving pockets embedded thereing and having axes substantially symmetrically spaced around and parallel to the axis of said base member, stacks of carbon disks retained within said pockets, electrical conductors embedded in said base member to series connect said stacks together in pairs at the bottoms of said pockets, and an inverted cup-shaped pedal member positioned in coaxial telescoping relation with said base member to form therewith a closed casing for the controller, said pedal member carrying resilient currentconductors and being linearly movable in an axial direction to connect and disconnect in series said series pairs oi stacks and to vary the pressure on said stacks.

6. A rheostatic controller comprising a stationary base former with a centrally-disposed body portion containing a central axial aperture and a plurality oi upright receiving pockets positioned equidistantly from said aperture and from each other, and having a continuous upturned peripheral edge portionl a plurality of compressible resistor units positioned in said receiving pockets, electrical conductors embedded in said base and extending between the bottom of pairs of adjacent pockets to connect the resistor units positioned therein in series, a; movable inverted cup-like pedal member Iormed with a central nect said paired resistor units in series and to increase the pressure thereon responsive to downward movement of the pedal member, said pedal member having a downturned edge portion which vertically overlies the upturned edge portion of said base in movable coaxial telescoping relation therewith. l

'1. A rheostatic controller comprising a lower stationary base of molded insulating material formed with a. centrally-disposed body portion containing upright receiving pockets, and having a continuous upturned peripheral edge portion, a plurality of compressible resistor units positioned in said receiving pockets and series connected in pairs at the bottom by embedded electrical conductors, an upper vertically mov-` able inverted cup-like pedal member having a downturned edge portion which vertically overlies the upturned edge portion of said base in movable coaxial telescoping relation therewith, said pedal member carrying resilient electrical conducting members positioned to connect said guide boss which slides within the axial aperture in said base, and resilient conductor means carried by said pedal member to electrically conpairs' of resistor units in series relation and to apply increasing pressure to said units as said pedal member is moved downward.

8.' A rheostatic controller comprising a lower stationary generally cylindrical base formed with a centrally-disposed body portion containing a central axial aperture and upright cylindrical receiving pockets, and having a continuous upturned peripheral edge portion, a, plurality of compressible resistor units positioned in said receiving pockets and series connected in pairs at the bottom by embedded electrical conductors, an upper movable inverted cup-like pedal member formed with a depending central guide boss which slides within the axial aperture 1n said base, said pedal member having a downturnedk edge portion which vertically overlies the upturned edge portion of said base in movable coaxial telescoping relation therewith, said pedal member carrying resilient electrical conducting members arranged to connect said pairs of resistor units in series relation and to apply increasing pressure to said units as said pedal member is moved downward. v

9. A rheostatic controller comprising a stationary generally cylindrical base formed with a centrally-disposed body portion containing a central axial aperture and a plurality o! upright cylindrical receiving pockets, and having a continuous upturned peripheral edge portion, a plurality of compressible resistor units positioned in said receiving pockets, current-conducting members connecting said resistor units together in pairs at the bottoms of adjacent pockets, a movable inverted cup-like pedal member formed with a central depending guide boss which slides within the axial aperture in said base, said pedal member having a downturned edge portion which vertically overlies the upturned edge portion of said base in movable coaxial telescoping relation therewith, a spring embracing said guide boss and urging said pedal member upward relative to said base, and a single headed screw positioned within said axial aperture and threaded into the pedal member to limit its upward movement, and resilient electrical conducting members carried by said pedal member and arranged to connect said pairs of resistor units in series relation and to apply increasing pressure to said units as said pedal member is moved downward.

KENNETH PERKINS. 

